Ptonomy Wallace / Mainframe

Ptonomy is a mutant who can read and walk through memories, put to work helping David Haller sort truth from delusion inside his own head. Calm, precise, a little wry, he treats other people's pasts like terrain to be mapped rather than mystery to be feared, and he seems to trust his own method completely.

Jeremie Harris plays him as the one adult in the room, someone whose gift should be the show's steadiest tool, which makes it land harder whenever Legion's unreliable-narrator games make even his certainty wobble. His dry composure is the calibration point against which the show's visual chaos gets measured.